Multi-speed planetary transmission

ABSTRACT

A multi-speed transmission including a plurality of planetary gearsets and a plurality of selective couplers to achieve at least nine forward speed ratios is disclosed. The plurality of planetary gearsets may include a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. The plurality of selective couplers may include a number of clutches and a number of brakes. The multi-speed transmission may have four planetary gearsets and six selective couplers. The six selective couplers may include four clutches and two brakes or three clutches and three brakes.

RELATED APPLICATION

This application is a divisional application of U.S. Non-Provisionalapplication Ser. No. 15/483,027, filed Apr. 10, 2017, titled MULTI-SPEEDPLANETARY TRANSMISSION, docket AT-P16001-US-ORD-01, which claims thebenefit of U.S. Provisional Application Ser. No. 62/400,691, filed Sep.28, 2016, titled MULTI-SPEED PLANETARY TRANSMISSION, docketAT-P16001USP1, the entire disclosures of which are expresslyincorporated by reference herein.

FIELD OF THE DISCLOSURE

The present disclosure relates to a multi-speed transmission and inparticular to a multi-speed transmission including a plurality ofplanetary gearsets and a plurality of selective couplers to achieve atleast nine forward speed ratios and at least one reverse speed ratio.

BACKGROUND OF THE DISCLOSURE

Multi-speed transmissions use a plurality of planetary gearsets,selective couplers, interconnectors, and additional elements to achievea plurality of forward and reverse speed ratios. Exemplary multi-speedtransmissions are disclosed in US Published Patent Application No.2016/0047440, Ser. No. 14/457,592, titled MULTI-SPEED TRANSMISSION,filed Aug. 12, 2014, the entire disclosure of which is expresslyincorporated by reference herein.

SUMMARY

The present disclosure provides a multi-speed transmission including aplurality of planetary gearsets and a plurality of selective couplers toachieve at least nine forward speed ratios. The plurality of planetarygearsets may include a first planetary gearset, a second planetarygearset, a third planetary gearset, and a fourth planetary gearset. Theplurality of selective couplers may include a number of clutches and anumber of brakes. In one example, the present disclosure provides amulti-speed transmission having four planetary gearsets and sixselective couplers. The six selective couplers may include four clutchesand two brakes. The six selective couplers may include three clutchesand three brakes.

In some instances throughout this disclosure and in the claims, numericterminology, such as first, second, third, and fourth, is used inreference to various gearsets, gears, gearset components,interconnectors, selective couplers, and other components. Such use isnot intended to denote an ordering of the components. Rather, numericterminology is used to assist the reader in identifying the componentbeing referenced and should not be narrowly interpreted as providing aspecific order of components. For example, a first planetary gearsetidentified in the drawings may support any one of the plurality ofplanetary gearsets recited in the claims, including the first planetarygearset, the second planetary gearset, the third planetary gearset, andthe fourth planetary gearset, depending on the language of the claims.

According to an exemplary embodiment of the present disclosure, atransmission is provided. The transmission comprising an at least onestationary member; an input member rotatable relative to the at leastone stationary member; a plurality of planetary gearsets operativelycoupled to the input member; an output member operatively coupled to theinput member through the plurality of planetary gearsets and rotatablerelative to the at least one stationary member; a first interconnectorfixedly couples the second gearset component of the first planetarygearset to one of the second planetary gearset and the third planetarygearset; a second interconnector fixedly couples the third gearsetcomponent of the first planetary gearset to at least one of the secondplanetary gearset, the third planetary gearset, and the fourth planetarygearset; and a plurality of selective couplers. The plurality ofselective couplers includes a first number of clutches and a secondnumber of brakes, wherein the first number is at least equal to thesecond number. Each of the plurality of planetary gearsets includes afirst gearset component, a second gearset component, and a third gearsetcomponent. The plurality of planetary gearsets including a firstplanetary gearset, a second planetary gearset, a third planetarygearset, and a fourth planetary gearset. The input member is fixedlycoupled to the first gearset component of the first planetary gearset.The output member is fixedly coupled to the fourth planetary gearset.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of thisdisclosure, and the manner of attaining them, will become more apparentand will be better understood by reference to the following descriptionof exemplary embodiments taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a diagrammatic view of a first exemplary multi-speedtransmission including four planetary gearsets and six selectivecouplers;

FIG. 2 is a truth table illustrating the selective engagement of the sixselective couplers of FIG. 1 to provide ten forward gear or speed ratiosand a reverse gear or speed ratio of the multi-speed transmission ofFIG. 1;

FIG. 3 is a diagrammatic view of a second exemplary multi-speedtransmission including four planetary gearsets and six selectivecouplers; and

FIG. 4 is a truth table illustrating the selective engagement of the sixselective couplers of FIG. 3 to provide nine forward gear or speedratios and a reverse gear or speed ratio of the multi-speed transmissionof FIG. 3;

FIG. 5 is a diagrammatic view of a third exemplary multi-speedtransmission including four planetary gearsets and six selectivecouplers;

FIG. 6 is a truth table illustrating the selective engagement of the sixselective couplers of FIG. 5 to provide ten forward gear or speed ratiosand a reverse gear or speed ratio of the multi-speed transmission ofFIG. 5;

FIG. 7 is a diagrammatic view of a fourth exemplary multi-speedtransmission including four planetary gearsets and six selectivecouplers;

FIG. 8 is a truth table illustrating the selective engagement of the sixselective couplers of FIG. 7 to provide nine forward gear or speedratios and a reverse gear or speed ratio of the multi-speed transmissionof FIG. 7;

FIG. 9 is a diagrammatic view of a fifth exemplary multi-speedtransmission including four planetary gearsets and six selectivecouplers;

FIG. 10 is a truth table illustrating the selective engagement of thesix selective couplers of FIG. 9 to provide ten forward gear or speedratios and a reverse gear or speed ratio of the multi-speed transmissionof FIG. 9;

FIG. 11 is a diagrammatic view of a sixth exemplary multi-speedtransmission including four planetary gearsets and six selectivecouplers; and

FIG. 12 is a truth table illustrating the selective engagement of thesix selective couplers of FIG. 11 to provide nine forward gear or speedratios and a reverse gear or speed ratio of the multi-speed transmissionof FIG. 11.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference is now made to the embodiments illustratedin the drawings, which are described below. The embodiments disclosedbelow are not intended to be exhaustive or limit the present disclosureto the precise form disclosed in the following detailed description.Rather, the embodiments are chosen and described so that others skilledin the art may utilize their teachings. Therefore, no limitation of thescope of the present disclosure is thereby intended. Correspondingreference characters indicate corresponding parts throughout the severalviews.

In the illustrated transmission embodiments, selective couplers aredisclosed. A selective coupler is a device which may be actuated tofixedly couple two or more components together. A selective couplerfixedly couples two or more components to rotate together as a unit whenthe selective coupler is in an engaged configuration. Further, the twoor more components may be rotatable relative to each other when theselective coupler is in a disengaged configuration. The terms “couples”,“coupled”, “coupler” and variations thereof are used to include botharrangements wherein the two or more components are in direct physicalcontact and arrangements wherein the two or more components are not indirect contact with each other (e.g., the components are “coupled” viaat least a third component), but yet still cooperate or interact witheach other.

A first exemplary selective coupler is a clutch. A clutch couples two ormore rotating components to one another so that the two or more rotatingcomponents rotate together as a unit in an engaged configuration andpermits relative rotation between the two or more rotating components inthe disengaged position. Exemplary clutches may be shiftablefriction-locked multi-disk clutches, shiftable form-locking claw orconical clutches, wet clutches, or any other known form of a clutch.

A second exemplary selective coupler is a brake. A brake couples one ormore rotatable components to a stationary component to hold the one ormore rotatable components stationary relative to the stationarycomponent in the engaged configuration and permits rotation of the oneor more components relative to the stationary component in thedisengaged configuration. Exemplary brakes may be configured asshiftable-friction-locked disk brakes, shiftable friction-locked bandbrakes, shiftable form-locking claw or conical brakes, or any otherknown form of a brake.

Selective couplers may be actively controlled devices or passivedevices. Exemplary actively controlled devices include hydraulicallyactuated clutch or brake elements and electrically actuated clutch orbrake elements. Additional details regarding systems and methods forcontrolling selective couplers are disclosed in the above-incorporatedUS Published Patent Application No. 2016/0047440.

In addition to coupling through selective couplers, various componentsof the disclosed transmission embodiments may be fixedly coupledtogether continuously throughout the operation of the disclosedtransmissions. Components may be fixedly coupled together eitherpermanently or removably. Components may be fixedly coupled togetherthrough spline connections, press fitting, fasteners, welding, machinedor formed functional portions of a unitary piece, or other suitablemethods of connecting components.

The disclosed transmission embodiments include a plurality of planetarygearsets. Each planetary gearset includes at least four components: asun gear; a ring gear; a plurality of planet gears; and a carrier thatis rotatably coupled to and carries the planet gears. In the case of asimple planetary gearset, the teeth of the sun gear are intermeshed withthe teeth of the planet gears which are in turn engaged with the teethof the ring gear. Each of these components may also be referred to as agearset component. It will be apparent to one of skill in the art thatsome planetary gearsets may include further components than thoseexplicitly identified. For example, one or more of the planetarygearsets may include two sets of planet gears. A first set of planetgears may intermesh with the sun gear while the second set of planetgears intermesh with the first set of planet gears and the ring gear.Both sets of planet gears are carried by the planet carrier.

One or more rotating components, such as shafts, drums, and othercomponents, may be collectively referred to as an interconnector whenthe one or more components are fixedly coupled together. Interconnectorsmay further be fixedly coupled to one or more gearset components and/orone or more selective couplers.

An input member of the disclosed transmission embodiments is rotated bya prime mover. Exemplary prime movers include internal combustionengines, electric motors, hybrid power systems, and other suitable powersystems. In one embodiment, the prime mover indirectly rotates the inputmember through a clutch and/or a torque converter. An output member ofthe disclosed transmission embodiments provides rotational power to oneor more working components. Exemplary working components include one ormore drive wheels of a motor vehicle, a power take-off shaft, and othersuitable devices. The output member is rotated based on theinterconnections of the gearset components and the selective couplers ofthe transmission. By changing the interconnections of the gearsetcomponents and the selective couplers, a rotation speed of the outputmember may be varied from a rotation speed of the input member.

The disclosed transmission embodiments are capable of transferringtorque from the input member to the output member and rotating theoutput member in at least nine forward gear or speed ratios relative tothe input member, illustratively ten forward gear or speed ratios forsome embodiments, and one reverse gear or speed ratio wherein therotation direction of the output member is reversed relative to itsrotation direction for the at least nine forward ratios. Exemplary gearratios that may be obtained using the embodiments of the presentdisclosure are disclosed herein. Of course, other gear ratios areachievable depending on the characteristics of the gearsets utilized.Exemplary characteristics include respective gear diameters, the numberof gear teeth, and the configurations of the various gears.

FIG. 1 is a diagrammatic representation of a multi-speed transmission100. Multi-speed transmission 100 includes an input member 102 and anoutput member 104. Each of input member 102 and output member 104 isrotatable relative to at least one stationary member 106. An exemplaryinput member 102 is an input shaft or other suitable rotatablecomponent. An exemplary output member 104 is an output shaft or othersuitable rotatable component. An exemplary stationary member 106 is ahousing of multi-speed transmission 100. The housing may include severalcomponents coupled together.

Multi-speed transmission 100 includes a plurality of planetary gearsets,illustratively a first planetary gearset 108, a second planetary gearset110, a third planetary gearset 112, and a fourth planetary gearset 114.In one embodiment, additional planetary gearsets may be included.Further, although first planetary gearset 108, second planetary gearset110, third planetary gearset 112, and fourth planetary gearset 114 areillustrated as simple planetary gearsets, it is contemplated thatcompound planetary gearsets may be included in some embodiments.

In one embodiment, multi-speed transmission 100 is arranged asillustrated in FIG. 1, with first planetary gearset 108 positionedbetween a first location or end 116 at which input member 102 entersstationary member 106 and second planetary gearset 110, second planetarygearset 110 is positioned between first planetary gearset 108 and thirdplanetary gearset 112, third planetary gearset 112 is positioned betweensecond planetary gearset 110 and fourth planetary gearset 114, andfourth planetary gearset 114 is positioned between third planetarygearset 112 and a second location or end 118 at which output member 104exits stationary member 106. In alternative embodiments, first planetarygearset 108, second planetary gearset 110, third planetary gearset 112,and fourth planetary gearset 114 are arranged in any order relative tolocation 116 and location 118. In the illustrated embodiment of FIG. 1,each of first planetary gearset 108, second planetary gearset 110, thirdplanetary gearset 112, and fourth planetary gearset 114 are axiallyaligned. In one example, input member 102 and output member 104 are alsoaxially aligned with first planetary gearset 108, second planetarygearset 110, third planetary gearset 112, and fourth planetary gearset114. In alternative embodiments, one or more of input member 102, outputmember 104, first planetary gearset 108, second planetary gearset 110,third planetary gearset 112, and fourth planetary gearset 114 are offsetand not axially aligned with the remainder.

First planetary gearset 108 includes a sun gear 120, a planet carrier122 supporting a plurality of planet gears 124, and a ring gear 126.Second planetary gearset 110 includes a sun gear 130, a planet carrier132 supporting a plurality of planet gears 134, and a ring gear 136.Third planetary gearset 112 includes a sun gear 140, a planet carrier142 supporting a plurality of planet gears 144, and a ring gear 146.Fourth planetary gearset 114 includes a sun gear 150, a planet carrier152 supporting a plurality of planet gears 154, and a ring gear 156.

Multi-speed transmission 100 further includes a plurality of selectivecouplers, illustratively a first selective coupler 162, a secondselective coupler 164, a third selective coupler 166, a fourth selectivecoupler 168, a fifth selective coupler 170, and a sixth selectivecoupler 172. In the illustrated embodiment, first selective coupler 162and second selective coupler 164 are brakes and third selective coupler166, fourth selective coupler 168, fifth selective coupler 170, andsixth selective coupler 172 are clutches. The axial locations of theclutches and brakes relative to the plurality of planetary gearsets maybe altered from the illustrated axial locations. In alternativeembodiments, any number of clutches and brakes may be used.

Multi-speed transmission 100 includes several components that areillustratively shown as being fixedly coupled together. Input member 102is fixedly coupled to sun gear 120 of first planetary gearset 108 andsun gear 130 of second planetary gearset 110. Output member 104 isfixedly coupled to ring gear 156 of fourth planetary gearset 114. Ringgear 126 of first planetary gearset 108, ring gear 136 of secondplanetary gearset 110, and sun gear 150 of fourth planetary gearset 114are fixedly coupled together. Planet carrier 122 of first planetarygearset 108 is fixedly coupled to ring gear 146 of third planetarygearset 112. In alternative embodiments, one or more of the componentsfixedly coupled together are selectively coupled together through one ormore selective couplers.

Multi-speed transmission 100 may be described as having eightinterconnectors. Input member 102 is a first interconnector that bothprovides input torque to multi-speed transmission 100 and fixedlycouples sun gear 120 of first planetary gearset 108 to sun gear 130 ofsecond planetary gearset 110. Input member 102 is further fixedlycoupled to third selective coupler 166. Output member 104 is a secondinterconnector that provides output torque from multi-speed transmission100. A third interconnector 180 fixedly couples ring gear 126 of firstplanetary gearset 108, ring gear 136 of second planetary gearset 110,and sun gear 150 of fourth planetary gearset 114 together. Thirdinterconnector 180 is further fixedly coupled to fourth selectivecoupler 168. A fourth interconnector 182 fixedly couples planet carrier122 of first planetary gearset 108 to ring gear 146 of third planetarygearset 112. A fifth interconnector 184 fixedly couples planet carrier132 of second planetary gearset 110 to fifth selective coupler 170. Asixth interconnector 186 fixedly couples planet carrier 152 of fourthplanetary gearset 114, third selective coupler 166, fifth selectivecoupler 170, and sixth selective coupler 172 together. A seventhinterconnector 188 fixedly couples planet carrier 142 of third planetarygearset 112 to first selective coupler 162 and to fourth selectivecoupler 168. An eighth interconnector 190 fixedly couples sun gear 140of third planetary gearset 112 to second selective coupler 164 and tosixth selective coupler 172.

Multi-speed transmission 100 further includes several components thatare illustratively shown as being selectively coupled together throughselective couplers. First selective coupler 162, when engaged, fixedlycouples planet carrier 142 of third planetary gearset 112 to stationarymember 106. When first selective coupler 162 is engaged, planet carrier142 of third planetary gearset 112 and stationary member 106 are lockedtogether. When first selective coupler 162 is disengaged, planet carrier142 of third planetary gearset 112 may rotate relative to stationarymember 106.

Second selective coupler 164, when engaged, fixedly couples sun gear 140of third planetary gearset 112 to stationary member 106. When secondselective coupler 164 is disengaged, sun gear 140 of third planetarygearset 112 may rotate relative to stationary member 106.

Third selective coupler 166, when engaged, fixedly couples sun gear 120of first planetary gearset 108 and sun gear 130 of second planetarygearset 110 to planet carrier 152 of fourth planetary gearset 114. Whenthird selective coupler 166 is disengaged, planet carrier 152 of fourthplanetary gearset 114 may rotate relative to sun gear 120 of firstplanetary gearset 108 and sun gear 130 of second planetary gearset 110.

Fourth selective coupler 168, when engaged, fixedly couples planetcarrier 142 of third planetary gearset 112 to third interconnector 180and thus to ring gear 126 of first planetary gearset 108, ring gear 136of second planetary gearset 110, and sun gear 150 of fourth planetarygearset 114. When fourth selective coupler 168 is disengaged, planetcarrier 142 of third planetary gearset 112 may rotate relative to thirdinterconnector 180 and thus relative to ring gear 126 of first planetarygearset 108, ring gear 136 of second planetary gearset 110, and sun gear150 of fourth planetary gearset 114.

Fifth selective coupler 170, when engaged, fixedly couples planetcarrier 132 of second planetary gearset 110 to planet carrier 152 offourth planetary gearset 114. When fifth selective coupler 170 isdisengaged, planet carrier 132 of second planetary gearset 110 mayrotate relative to planet carrier 152 of fourth planetary gearset 114.

Sixth selective coupler 172, when engaged, fixedly couples planetcarrier 152 of fourth planetary gearset 114 to sun gear 140 of thirdplanetary gearset 112. When sixth selective coupler 172 is disengaged,planet carrier 152 of fourth planetary gearset 114 may rotate relativeto sun gear 140 of third planetary gearset 112.

By engaging various combinations of first selective coupler 162, secondselective coupler 164, third selective coupler 166, fourth selectivecoupler 168, fifth selective coupler 170, and sixth selective coupler172, additional components of multi-speed transmission 100 may befixedly coupled together.

The plurality of planetary gearsets and the plurality of selectivecouplers of multi-speed transmission 100 may be interconnected invarious arrangements to provide torque from input member 102 to outputmember 104 in at least nine forward gear or speed ratios and one reversegear or speed ratio. Referring to FIG. 2, an exemplary truth table 200is shown that provides the state of each of first selective coupler 162,second selective coupler 164, third selective coupler 166, fourthselective coupler 168, fifth selective coupler 170, and sixth selectivecoupler 172 for ten different forward gear or speed ratios and onereverse gear or speed ratio. Each row corresponds to a giveninterconnection arrangement for transmission 100. The first columnprovides the gear range (reverse and 1^(st)-10^(th) forward gears). Thesecond column provides the gear ratio between the input member 102 andthe output member 104. The third column provides the gear step. The sixrightmost columns illustrate which ones of the selective couplers162-172 are engaged (“1” indicates engaged) and which ones of selectivecouplers 162-172 are disengaged (“(blank)” indicates disengaged). FIG. 2is only one example of any number of truth tables possible for achievingat least nine forward ratios and one reverse ratio.

In the example of FIG. 2, the illustrated reverse ratio (Rev) isachieved by having second selective coupler 164, fourth selectivecoupler 168, and sixth selective coupler 172 in an engaged configurationand first selective coupler 162, third selective coupler 166, and fifthselective coupler 170 in a disengaged configuration.

In one embodiment, to place multi-speed transmission 100 in neutral(Neu), all of first selective coupler 162, second selective coupler 164,third selective coupler 166, fourth selective coupler 168, fifthselective coupler 170, and sixth selective coupler 172 are in thedisengaged configuration. One or more of first selective coupler 162,second selective coupler 164, third selective coupler 166, fourthselective coupler 168, fifth selective coupler 170, and sixth selectivecoupler 172 may remain engaged in neutral (Neu) as long as thecombination of first selective coupler 162, second selective coupler164, third selective coupler 166, fourth selective coupler 168, fifthselective coupler 170, and sixth selective coupler 172 does not transmittorque from input member 102 to output member 104.

A first forward ratio (shown as 1st) in truth table 200 of FIG. 2 isachieved by having first selective coupler 162, second selective coupler164, and sixth selective coupler 172 in an engaged configuration andthird selective coupler 166, fourth selective coupler 168, and fifthselective coupler 170 in a disengaged configuration.

A second or subsequent forward ratio (shown as 2nd) in truth table 200of FIG. 2 is achieved by having second selective coupler 164, fifthselective coupler 170, and sixth selective coupler 172 in an engagedconfiguration and first selective coupler 162, third selective coupler166, and fourth selective coupler 168 in a disengaged configuration.Therefore, when transitioning between the first forward ratio and thesecond forward ratio, first selective coupler 162 is placed in thedisengaged configuration and fifth selective coupler 170 is placed inthe engaged configuration.

A third or subsequent forward ratio (shown as 3rd) in truth table 200 ofFIG. 2 is achieved by having first selective coupler 162, secondselective coupler 164, and fifth selective coupler 170 in an engagedconfiguration and third selective coupler 166, fourth selective coupler168, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the second forward ratio and thethird forward ratio, sixth selective coupler 172 is placed in thedisengaged configuration and first selective coupler 162 is placed inthe engaged configuration.

A fourth or subsequent forward ratio (shown as 4th) in truth table 200of FIG. 2 is achieved by having first selective coupler 162, fourthselective coupler 168, and fifth selective coupler 170 in an engagedconfiguration and second selective coupler 164, third selective coupler166, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the third forward ratio and thefourth forward ratio, second selective coupler 164 is placed in thedisengaged configuration and fourth selective coupler 168 is placed inthe engaged configuration.

A fifth or subsequent forward ratio (shown as 5th) in truth table 200 ofFIG. 2 is achieved by having second selective coupler 164, fourthselective coupler 168, and fifth selective coupler 170 in an engagedconfiguration and first selective coupler 162, third selective coupler166, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the fourth forward ratio and thefifth forward ratio, first selective coupler 162 is placed in thedisengaged configuration and second selective coupler 164 is placed inthe engaged configuration.

A sixth or subsequent forward ratio (shown as 6th) in truth table 200 ofFIG. 2 is achieved by having second selective coupler 164, thirdselective coupler 166, and fifth selective coupler 170 in an engagedconfiguration and first selective coupler 162, fourth selective coupler168, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the fifth forward ratio and thesixth forward ratio, fourth selective coupler 168 is placed in thedisengaged configuration and third selective coupler 166 is placed inthe engaged configuration.

A seventh or subsequent forward ratio (shown as 7th) in truth table 200of FIG. 2 is achieved by having second selective coupler 164, thirdselective coupler 166, and fourth selective coupler 168 in an engagedconfiguration and first selective coupler 162, fifth selective coupler170, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the sixth forward ratio and theseventh forward ratio, fifth selective coupler 170 is placed in thedisengaged configuration and fourth selective coupler 168 is placed inthe engaged configuration.

An eighth or subsequent forward ratio (shown as 8th) in truth table 200of FIG. 2 is achieved by having first selective coupler 162, thirdselective coupler 166, and fourth selective coupler 168 in an engagedconfiguration and second selective coupler 164, fifth selective coupler170, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the seventh forward ratio and theeighth forward ratio, second selective coupler 164 is placed in thedisengaged configuration and first selective coupler 162 is placed inthe engaged configuration.

A ninth or subsequent forward ratio (shown as 9th) in truth table 200 ofFIG. 2 is achieved by having first selective coupler 162, secondselective coupler 164, and third selective coupler 166 in an engagedconfiguration and fourth selective coupler 168, fifth selective coupler170, and sixth selective coupler 172 in a disengaged configuration.Therefore, when transitioning between the eighth forward ratio and theninth forward ratio, fourth selective coupler 168 is placed in thedisengaged configuration and second selective coupler 164 is placed inthe engaged configuration.

A tenth or subsequent forward ratio (shown as 10th) in truth table 200of FIG. 2 is achieved by having first selective coupler 162, thirdselective coupler 166, and sixth selective coupler 172 in an engagedconfiguration and second selective coupler 164, fourth selective coupler168, and fifth selective coupler 170 in a disengaged configuration.Therefore, when transitioning between the ninth forward ratio and thetenth forward ratio, second selective coupler 164 is placed in thedisengaged configuration and sixth selective coupler 172 is placed inthe engaged configuration.

Referring to FIG. 3, another exemplary multi-speed transmission 250 isillustrated. The kinematics of multi-speed transmission 250 aregenerally identical to multi-speed transmission 100 with the followingdifferences. First, interconnector 252 of multi-speed transmission 250fixedly couples sun gear 140 of third planetary gearset 112 to secondselective coupler 164, but not also to the sixth selective coupler asaccomplished by eighth interconnector 190 of multi-speed transmission100. Second, sixth selective coupler 254 of multi-speed transmission250, when engaged, fixedly couples planet carrier 152 of fourthplanetary gearset 114 to stationary member 106, not to sun gear 140 ofthird planetary gearset 112 as accomplished by sixth selective coupler172 of multi-speed transmission 100. When sixth selective coupler 254 ofmulti-speed transmission 250 is disengaged, planet carrier 152 of fourthplanetary gearset 114 may rotate relative to stationary member 106.Multi-speed transmission 250 has an equal number of clutches, thirdselective coupler 166, fourth selective coupler 168, and fifth selectivecoupler 170, and brakes, first selective coupler 162, second selectivecoupler 164, and sixth selective coupler 254.

The plurality of planetary gearsets and the plurality of selectivecouplers of multi-speed transmission 250 may be interconnected invarious arrangements to provide torque from input member 102 to outputmember 104 in at least nine forward gear or speed ratios and one reversegear or speed ratio. Referring to FIG. 4, an exemplary truth table 260is shown that provides the state of each of first selective coupler 162,second selective coupler 164, third selective coupler 166, fourthselective coupler 168, fifth selective coupler 170, and sixth selectivecoupler 254 for nine different forward gear or speed ratios and onereverse gear or speed ratio. Each row corresponds to a giveninterconnection arrangement for transmission 250. The first columnprovides the gear range (reverse and 1^(th)-9^(th) forward gears). Thesecond column provides the gear ratio between the input member 102 andthe output member 104. The third column provides the gear step. The sixrightmost columns illustrate which ones of the selective couplers162-170 and 254 are engaged (“1” indicates engaged) and which ones ofselective couplers 162-170 and 254 are disengaged (“(blank)” indicatesdisengaged). FIG. 4 is only one example of any number of truth tablespossible for achieving at least nine forward ratios and one reverseratio.

In the example of FIG. 4, the illustrated reverse ratio (Rev) isachieved by having second selective coupler 164, fourth selectivecoupler 168, and sixth selective coupler 254 in an engaged configurationand first selective coupler 162, third selective coupler 166, and fifthselective coupler 170 in a disengaged configuration.

In one embodiment, to place multi-speed transmission 250 in neutral(Neu), all of first selective coupler 162, second selective coupler 164,third selective coupler 166, fourth selective coupler 168, fifthselective coupler 170, and sixth selective coupler 254 are in thedisengaged configuration. One or more of first selective coupler 162,second selective coupler 164, third selective coupler 166, fourthselective coupler 168, fifth selective coupler 170, and sixth selectivecoupler 254 may remain engaged in neutral (Neu) as long as thecombination of first selective coupler 162, second selective coupler164, third selective coupler 166, fourth selective coupler 168, fifthselective coupler 170, and sixth selective coupler 254 does not transmittorque from input member 102 to output member 104.

A first forward ratio (shown as 1st) in truth table 260 of FIG. 4 isachieved by having first selective coupler 162, second selective coupler164, and sixth selective coupler 254 in an engaged configuration andthird selective coupler 166, fourth selective coupler 168, and fifthselective coupler 170 in a disengaged configuration.

A second or subsequent forward ratio (shown as 2nd) in truth table 260of FIG. 4 is achieved by having second selective coupler 164, fifthselective coupler 170, and sixth selective coupler 254 in an engagedconfiguration and first selective coupler 162, third selective coupler166, and fourth selective coupler 168 in a disengaged configuration.Therefore, when transitioning between the first forward ratio and thesecond forward ratio, first selective coupler 162 is placed in thedisengaged configuration and fifth selective coupler 170 is placed inthe engaged configuration.

A third or subsequent forward ratio (shown as 3rd) in truth table 260 ofFIG. 4 is achieved by having first selective coupler 162, secondselective coupler 164, and fifth selective coupler 170 in an engagedconfiguration and third selective coupler 166, fourth selective coupler168, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the second forward ratio and thethird forward ratio, sixth selective coupler 254 is placed in thedisengaged configuration and first selective coupler 162 is placed inthe engaged configuration.

A fourth or subsequent forward ratio (shown as 4th) in truth table 260of FIG. 4 is achieved by having first selective coupler 162, fourthselective coupler 168, and fifth selective coupler 170 in an engagedconfiguration and second selective coupler 164, third selective coupler166, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the third forward ratio and thefourth forward ratio, second selective coupler 164 is placed in thedisengaged configuration and fourth selective coupler 168 is placed inthe engaged configuration.

A fifth or subsequent forward ratio (shown as 5th) in truth table 260 ofFIG. 4 is achieved by having second selective coupler 164, fourthselective coupler 168, and fifth selective coupler 170 in an engagedconfiguration and first selective coupler 162, third selective coupler166, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the fourth forward ratio and thefifth forward ratio, first selective coupler 162 is placed in thedisengaged configuration and second selective coupler 164 is placed inthe engaged configuration.

A sixth or subsequent forward ratio (shown as 6th) in truth table 260 ofFIG. 4 is achieved by having second selective coupler 164, thirdselective coupler 166, and fifth selective coupler 170 in an engagedconfiguration and first selective coupler 162, fourth selective coupler168, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the fifth forward ratio and thesixth forward ratio, fourth selective coupler 168 is placed in thedisengaged configuration and third selective coupler 166 is placed inthe engaged configuration.

A seventh or subsequent forward ratio (shown as 7th) in truth table 260of FIG. 4 is achieved by having second selective coupler 164, thirdselective coupler 166, and fourth selective coupler 168 in an engagedconfiguration and first selective coupler 162, fifth selective coupler170, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the sixth forward ratio and theseventh forward ratio, fifth selective coupler 170 is placed in thedisengaged configuration and fourth selective coupler 168 is placed inthe engaged configuration.

An eighth or subsequent forward ratio (shown as 8th) in truth table 260of FIG. 4 is achieved by having first selective coupler 162, thirdselective coupler 166, and fourth selective coupler 168 in an engagedconfiguration and second selective coupler 164, fifth selective coupler170, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the seventh forward ratio and theeighth forward ratio, second selective coupler 164 is placed in thedisengaged configuration and first selective coupler 162 is placed inthe engaged configuration.

A ninth or subsequent forward ratio (shown as 9th) in truth table 260 ofFIG. 4 is achieved by having first selective coupler 162, secondselective coupler 164, and third selective coupler 166 in an engagedconfiguration and fourth selective coupler 168, fifth selective coupler170, and sixth selective coupler 254 in a disengaged configuration.Therefore, when transitioning between the eighth forward ratio and theninth forward ratio, fourth selective coupler 168 is placed in thedisengaged configuration and second selective coupler 164 is placed inthe engaged configuration.

FIG. 5 is a diagrammatic representation of a multi-speed transmission300. Multi-speed transmission 300 includes an input member 302 and anoutput member 304. Each of input member 302 and output member 304 isrotatable relative to at least one stationary member 306. An exemplaryinput member 302 is an input shaft or other suitable rotatablecomponent. An exemplary output member 304 is an output shaft or othersuitable rotatable component. An exemplary stationary member 306 is ahousing of multi-speed transmission 300. The housing may include severalcomponents coupled together.

Multi-speed transmission 300 includes a plurality of planetary gearsets,illustratively a first planetary gearset 308, a second planetary gearset310, a third planetary gearset 312, and a fourth planetary gearset 314.In one embodiment, additional planetary gearsets may be included.Further, although first planetary gearset 308, second planetary gearset310, third planetary gearset 312, and fourth planetary gearset 314 areillustrated as simple planetary gearsets, it is contemplated thatcompound planetary gearsets may be included in some embodiments.

In one embodiment, multi-speed transmission 300 is arranged asillustrated in FIG. 5, with first planetary gearset 308 positionedbetween a first location or end 316 at which input member 302 entersstationary member 306 and second planetary gearset 310, second planetarygearset 310 is positioned between first planetary gearset 308 and thirdplanetary gearset 312, third planetary gearset 312 is positioned betweensecond planetary gearset 310 and fourth planetary gearset 314, andfourth planetary gearset 314 is positioned between third planetarygearset 312 and a second location or end 318 at which output member 304exits stationary member 306. In alternative embodiments, first planetarygearset 308, second planetary gearset 310, third planetary gearset 312,and fourth planetary gearset 314 are arranged in any order relative tolocation 316 and location 318. In the illustrated embodiment of FIG. 5,each of first planetary gearset 308, second planetary gearset 310, thirdplanetary gearset 312, and fourth planetary gearset 314 are axiallyaligned. In one example, input member 302 and output member 304 are alsoaxially aligned with first planetary gearset 308, second planetarygearset 310, third planetary gearset 312, and fourth planetary gearset314. In alternative embodiments, one or more of input member 302, outputmember 304, first planetary gearset 308, second planetary gearset 310,third planetary gearset 312, and fourth planetary gearset 314 are offsetand not axially aligned with the remainder.

First planetary gearset 308 includes a sun gear 320, a planet carrier322 supporting a plurality of planet gears 324, and a ring gear 326.Second planetary gearset 310 includes a sun gear 330, a planet carrier332 supporting a plurality of planet gears 334, and a ring gear 336.Third planetary gearset 312 includes a sun gear 340, a planet carrier342 supporting a plurality of planet gears 344, and a ring gear 346.Fourth planetary gearset 314 includes a sun gear 350, a planet carrier352 supporting a plurality of planet gears 354, and a ring gear 356.

Multi-speed transmission 300 further includes a plurality of selectivecouplers, illustratively a first selective coupler 362, a secondselective coupler 364, a third selective coupler 366, a fourth selectivecoupler 368, a fifth selective coupler 370, and a sixth selectivecoupler 372. In the illustrated embodiment, first selective coupler 362and second selective coupler 364 are brakes and third selective coupler366, fourth selective coupler 368, fifth selective coupler 370, andsixth selective coupler 372 are clutches. The axial locations of theclutches and brakes relative to the plurality of planetary gearsets maybe altered from the illustrated axial locations. In alternativeembodiments, any number of clutches and brakes may be used.

Multi-speed transmission 300 includes several components that areillustratively shown as being fixedly coupled together. Input member 302is fixedly coupled to sun gear 320 of first planetary gearset 308.Output member 304 is fixedly coupled to ring gear 356 of fourthplanetary gearset 314. Ring gear 326 of first planetary gearset 308, sungear 330 of second planetary gearset 310, and sun gear 350 of fourthplanetary gearset 314 are fixedly coupled together. Planet carrier 322of first planetary gearset 308 is fixedly coupled to ring gear 336 ofsecond planetary gearset 310. Planet carrier 332 of second planetarygearset 310 is fixedly coupled to ring gear 346 of third planetarygearset 312. In alternative embodiments, one or more of the componentsfixedly coupled together are selectively coupled together through one ormore selective couplers.

Multi-speed transmission 300 may be described as having eightinterconnectors. Input member 302 is a first interconnector that bothprovides input torque to multi-speed transmission 300 and fixedlycouples sun gear 320 of first planetary gearset 308 to third selectivecoupler 366. Output member 304 is a second interconnector that providesoutput torque from multi-speed transmission 300. A third interconnector380 fixedly couples ring gear 326 of first planetary gearset 308, sungear 330 of second planetary gearset 310, and sun gear 350 of fourthplanetary gearset 314 together. Third interconnector 380 is furtherfixedly coupled to fourth selective coupler 368. A fourth interconnector382 fixedly couples planet carrier 322 of first planetary gearset 308 toring gear 336 of second planetary gearset 310. Fourth interconnector 382is further fixedly coupled to fifth selective coupler 370. A fifthinterconnector 384 fixedly couples planet carrier 332 of secondplanetary gearset 310 to ring gear 346 of third planetary gearset 312. Asixth interconnector 386 fixedly couples planet carrier 352 of fourthplanetary gearset 314 to third selective coupler 366 and to sixthselective coupler 372. A seventh interconnector 388 fixedly couplesplanet carrier 342 of third planetary gearset 312 to first selectivecoupler 362 and to fourth selective coupler 368. An eighthinterconnector 390 fixedly couples sun gear 340 of third planetarygearset 312 to second selective coupler 364 and to sixth selectivecoupler 372.

Multi-speed transmission 300 further includes several components thatare illustratively shown as being selectively coupled together throughselective couplers. First selective coupler 362, when engaged, fixedlycouples planet carrier 342 of third planetary gearset 312 to stationarymember 306. When first selective coupler 362 is disengaged, planetcarrier 342 of third planetary gearset 312 may rotate relative tostationary member 306.

Second selective coupler 364, when engaged, fixedly couples sun gear 340of third planetary gearset 312 to stationary member 306. When secondselective coupler 364 is disengaged, sun gear 340 of third planetarygearset 312 may rotate relative to stationary member 306.

Third selective coupler 366, when engaged, fixedly couples sun gear 320of first planetary gearset 308 to planet carrier 352 of fourth planetarygearset 314. When third selective coupler 366 is disengaged, planetcarrier 352 of fourth planetary gearset 314 may rotate relative to sungear 320 of first planetary gearset 308.

Fourth selective coupler 368, when engaged, fixedly couples ring gear326 of first planetary gearset 308, sun gear 330 of second planetarygearset 310, and sun gear 350 of fourth planetary gearset 314 to planetcarrier 342 of third planetary gearset 312. When fourth selectivecoupler 368 is disengaged, planet carrier 342 of third planetary gearset312 may rotate relative to ring gear 326 of first planetary gearset 308,sun gear 330 of second planetary gearset 310, and sun gear 350 of fourthplanetary gearset 314.

Fifth selective coupler 370, when engaged, fixedly couples planetcarrier 322 of first planetary gearset 308 to planet carrier 352 offourth planetary gearset 314. When fifth selective coupler 370 isdisengaged, planet carrier 322 of first planetary gearset 308 may rotaterelative to planet carrier 352 of fourth planetary gearset 314.

Sixth selective coupler 372, when engaged, fixedly couples planetcarrier 352 of fourth planetary gearset 314 to sun gear 340 of thirdplanetary gearset 312 and to second selective coupler 364. When sixthselective coupler 372 is disengaged, planet carrier 352 of fourthplanetary gearset 314 may rotate relative to sun gear 340 of thirdplanetary gearset 312.

By engaging various combinations of first selective coupler 362, secondselective coupler 364, third selective coupler 366, fourth selectivecoupler 368, fifth selective coupler 370, and sixth selective coupler372, additional components of multi-speed transmission 300 may befixedly coupled together.

The plurality of planetary gearsets and the plurality of selectivecouplers of multi-speed transmission 300 may be interconnected invarious arrangements to provide torque from input member 302 to outputmember 304 in at least nine forward gear or speed ratios and one reversegear or speed ratio. Referring to FIG. 6, an exemplary truth table 400is shown that provides the state of each of first selective coupler 362,second selective coupler 364, third selective coupler 366, fourthselective coupler 368, fifth selective coupler 370, and sixth selectivecoupler 372 for ten different forward gear or speed ratios and onereverse gear or speed ratio. Each row corresponds to a giveninterconnection arrangement for transmission 300. The first columnprovides the gear range (reverse and 1^(th)-10^(th) forward gears). Thesecond column provides the gear ratio between the input member 302 andthe output member 304. The third column provides the gear step. The sixrightmost columns illustrate which ones of the selective couplers362-372 are engaged (“1” indicates engaged) and which ones of selectivecouplers 362-372 are disengaged (“(blank)” indicates disengaged). FIG. 4is only one example of any number of truth tables possible for achievingat least nine forward ratios and one reverse ratio.

In the example of FIG. 6, the illustrated reverse ratio (Rev) isachieved by having second selective coupler 364, fourth selectivecoupler 368, and sixth selective coupler 372 in an engaged configurationand first selective coupler 362, third selective coupler 366, and fifthselective coupler 370 in a disengaged configuration.

In one embodiment, to place multi-speed transmission 300 in neutral(Neu), all of first selective coupler 362, second selective coupler 364,third selective coupler 366, fourth selective coupler 368, fifthselective coupler 370, and sixth selective coupler 372 are in thedisengaged configuration. One or more of first selective coupler 362,second selective coupler 364, third selective coupler 366, fourthselective coupler 368, fifth selective coupler 370, and sixth selectivecoupler 372 may remain engaged in neutral (Neu) as long as thecombination of first selective coupler 362, second selective coupler364, third selective coupler 366, fourth selective coupler 368, fifthselective coupler 370, and sixth selective coupler 372 does not transmittorque from input member 302 to output member 304.

A first forward ratio (shown as 1st) in truth table 400 of FIG. 6 isachieved by having first selective coupler 362, second selective coupler364, and sixth selective coupler 372 in an engaged configuration andthird selective coupler 366, fourth selective coupler 368, and fifthselective coupler 370 in a disengaged configuration.

A second or subsequent forward ratio (shown as 2nd) in truth table 400of FIG. 6 is achieved by having second selective coupler 364, fifthselective coupler 370, and sixth selective coupler 372 in an engagedconfiguration and first selective coupler 362, third selective coupler366, and fourth selective coupler 368 in a disengaged configuration.Therefore, when transitioning between the first forward ratio and thesecond forward ratio, first selective coupler 362 is placed in thedisengaged configuration and fifth selective coupler 370 is placed inthe engaged configuration.

A third or subsequent forward ratio (shown as 3rd) in truth table 400 ofFIG. 6 is achieved by having first selective coupler 362, secondselective coupler 364, and fifth selective coupler 370 in an engagedconfiguration and third selective coupler 366, fourth selective coupler368, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the second forward ratio and thethird forward ratio, sixth selective coupler 372 is placed in thedisengaged configuration and first selective coupler 362 is placed inthe engaged configuration.

A fourth or subsequent forward ratio (shown as 4th) in truth table 400of FIG. 6 is achieved by having first selective coupler 362, fourthselective coupler 368, and fifth selective coupler 370 in an engagedconfiguration and second selective coupler 364, third selective coupler366, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the third forward ratio and thefourth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and fourth selective coupler 368 is placed inthe engaged configuration.

A fifth or subsequent forward ratio (shown as 5th) in truth table 400 ofFIG. 6 is achieved by having second selective coupler 364, fourthselective coupler 368, and fifth selective coupler 370 in an engagedconfiguration and first selective coupler 362, third selective coupler366, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the fourth forward ratio and thefifth forward ratio, first selective coupler 362 is placed in thedisengaged configuration and second selective coupler 364 is placed inthe engaged configuration.

A sixth or subsequent forward ratio (shown as 6th) in truth table 400 ofFIG. 6 is achieved by having third selective coupler 366, fourthselective coupler 368, and fifth selective coupler 370 in an engagedconfiguration and first selective coupler 362, second selective coupler364, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the fifth forward ratio and thesixth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and third selective coupler 366 is placed inthe engaged configuration.

A seventh or subsequent forward ratio (shown as 7th) in truth table 400of FIG. 6 is achieved by having second selective coupler 364, thirdselective coupler 366, and fourth selective coupler 368 in an engagedconfiguration and first selective coupler 362, fifth selective coupler370, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the sixth forward ratio and theseventh forward ratio, fifth selective coupler 370 is placed in thedisengaged configuration and second selective coupler 364 is placed inthe engaged configuration.

An eighth or subsequent forward ratio (shown as 8th) in truth table 400of FIG. 6 is achieved by having first selective coupler 362, thirdselective coupler 366, and fourth selective coupler 368 in an engagedconfiguration and second selective coupler 364, fifth selective coupler370, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the seventh forward ratio and theeighth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and first selective coupler 362 is placed inthe engaged configuration.

A ninth or subsequent forward ratio (shown as 9th) in truth table 400 ofFIG. 6 is achieved by having first selective coupler 362, secondselective coupler 364, and third selective coupler 366 in an engagedconfiguration and fourth selective coupler 368, fifth selective coupler370, and sixth selective coupler 372 in a disengaged configuration.Therefore, when transitioning between the eighth forward ratio and theninth forward ratio, fourth selective coupler 368 is placed in thedisengaged configuration and second selective coupler 364 is placed inthe engaged configuration.

A tenth or subsequent forward ratio (shown as 10th) in truth table 400of FIG. 6 is achieved by having first selective coupler 362, thirdselective coupler 366, and sixth selective coupler 372 in an engagedconfiguration and second selective coupler 364, fourth selective coupler368, and fifth selective coupler 370 in a disengaged configuration.Therefore, when transitioning between the ninth forward ratio and thetenth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and sixth selective coupler 372 is placed inthe engaged configuration.

Referring to FIG. 7, another exemplary multi-speed transmission 450 isillustrated. The kinematics of multi-speed transmission 450 aregenerally identical to multi-speed transmission 300 with the followingdifferences. First, sixth selective coupler 454 of multi-speedtransmission 450, when engaged, fixedly couples planet carrier 352 offourth planetary gearset 314 to stationary member 306, not to sun gear340 of third planetary gearset 312 as accomplished by sixth selectivecoupler 372 of multi-speed transmission 300. When sixth selectivecoupler 454 of multi-speed transmission 450 is disengaged, planetcarrier 352 of fourth planetary gearset 314 may rotate relative tostationary member 306. Second, interconnector 452 of multi-speedtransmission 450 fixedly couples sun gear 340 of third planetary gearset312 to second selective coupler 364, but not also to the sixth selectivecoupler as accomplished by eighth interconnector 390 of multi-speedtransmission 300. Multi-speed transmission 450 has an equal number ofclutches, third selective coupler 366, fourth selective coupler 368, andfifth selective coupler 370, and brakes, first selective coupler 362,second selective coupler 364, and sixth selective coupler 454.

The plurality of planetary gearsets and the plurality of selectivecouplers of multi-speed transmission 450 may be interconnected invarious arrangements to provide torque from input member 302 to outputmember 304 in at least nine forward gear or speed ratios and one reversegear or speed ratio. Referring to FIG. 8, an exemplary truth table 460is shown that provides the state of each of first selective coupler 362,second selective coupler 364, third selective coupler 366, fourthselective coupler 368, fifth selective coupler 370, and sixth selectivecoupler 454 for nine different forward gear or speed ratios and onereverse gear or speed ratio. Each row corresponds to a giveninterconnection arrangement for transmission 450. The first columnprovides the gear range (reverse and 1^(th)-9^(th) forward gears). Thesecond column provides the gear ratio between the input member 302 andthe output member 304. The third column provides the gear step. The sixrightmost columns illustrate which ones of the selective couplers362-370 and 454 are engaged (“1” indicates engaged) and which ones ofselective couplers 362-370 and 454 are disengaged (“(blank)” indicatesdisengaged). FIG. 8 is only one example of any number of truth tablespossible for achieving at least nine forward ratios and one reverseratio.

In the example of FIG. 8, the illustrated reverse ratio (Rev) isachieved by having second selective coupler 364, fourth selectivecoupler 368, and sixth selective coupler 454 in an engaged configurationand first selective coupler 362, third selective coupler 366, and fifthselective coupler 370 in a disengaged configuration.

In one embodiment, to place multi-speed transmission 450 in neutral(Neu), all of first selective coupler 362, second selective coupler 364,third selective coupler 366, fourth selective coupler 368, fifthselective coupler 370, and sixth selective coupler 454 are in thedisengaged configuration. One or more of first selective coupler 362,second selective coupler 364, third selective coupler 366, fourthselective coupler 368, fifth selective coupler 370, and sixth selectivecoupler 454 may remain engaged in neutral (Neu) as long as thecombination of first selective coupler 362, second selective coupler364, third selective coupler 366, fourth selective coupler 368, fifthselective coupler 370, and sixth selective coupler 454 does not transmittorque from input member 302 to output member 304.

A first forward ratio (shown as 1st) in truth table 460 of FIG. 8 isachieved by having first selective coupler 362, second selective coupler364, and sixth selective coupler 454 in an engaged configuration andthird selective coupler 366, fourth selective coupler 368, and fifthselective coupler 370 in a disengaged configuration.

A second or subsequent forward ratio (shown as 2nd) in truth table 460of FIG. 8 is achieved by having second selective coupler 364, fifthselective coupler 370, and sixth selective coupler 454 in an engagedconfiguration and first selective coupler 362, third selective coupler366, and fourth selective coupler 368 in a disengaged configuration.Therefore, when transitioning between the first forward ratio and thesecond forward ratio, first selective coupler 362 is placed in thedisengaged configuration and fifth selective coupler 370 is placed inthe engaged configuration.

A third or subsequent forward ratio (shown as 3rd) in truth table 460 ofFIG. 8 is achieved by having first selective coupler 362, secondselective coupler 364, and fifth selective coupler 370 in an engagedconfiguration and third selective coupler 366, fourth selective coupler368, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the second forward ratio and thethird forward ratio, sixth selective coupler 454 is placed in thedisengaged configuration and first selective coupler 362 is placed inthe engaged configuration.

A fourth or subsequent forward ratio (shown as 4th) in truth table 460of FIG. 8 is achieved by having first selective coupler 362, fourthselective coupler 368, and fifth selective coupler 370 in an engagedconfiguration and second selective coupler 364, third selective coupler366, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the third forward ratio and thefourth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and fourth selective coupler 368 is placed inthe engaged configuration.

A fifth or subsequent forward ratio (shown as 5th) in truth table 460 ofFIG. 8 is achieved by having second selective coupler 364, fourthselective coupler 368, and fifth selective coupler 370 in an engagedconfiguration and first selective coupler 362, third selective coupler366, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the fourth forward ratio and thefifth forward ratio, first selective coupler 362 is placed in thedisengaged configuration and second selective coupler 364 is placed inthe engaged configuration.

A sixth or subsequent forward ratio (shown as 6th) in truth table 460 ofFIG. 8 is achieved by having third selective coupler 366, fourthselective coupler 368, and fifth selective coupler 370 in an engagedconfiguration and first selective coupler 362, second selective coupler364, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the fifth forward ratio and thesixth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and third selective coupler 366 is placed inthe engaged configuration.

A seventh or subsequent forward ratio (shown as 7th) in truth table 460of FIG. 8 is achieved by having second selective coupler 364, thirdselective coupler 366, and fourth selective coupler 368 in an engagedconfiguration and first selective coupler 362, fifth selective coupler370, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the sixth forward ratio and theseventh forward ratio, fifth selective coupler 370 is placed in thedisengaged configuration and second selective coupler 364 is placed inthe engaged configuration.

An eighth or subsequent forward ratio (shown as 8th) in truth table 460of FIG. 8 is achieved by having first selective coupler 362, thirdselective coupler 366, and fourth selective coupler 368 in an engagedconfiguration and second selective coupler 364, fifth selective coupler370, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the seventh forward ratio and theeighth forward ratio, second selective coupler 364 is placed in thedisengaged configuration and first selective coupler 362 is placed inthe engaged configuration.

A ninth or subsequent forward ratio (shown as 9th) in truth table 460 ofFIG. 8 is achieved by having first selective coupler 362, secondselective coupler 364, and third selective coupler 366 in an engagedconfiguration and fourth selective coupler 368, fifth selective coupler370, and sixth selective coupler 454 in a disengaged configuration.Therefore, when transitioning between the eighth forward ratio and theninth forward ratio, fourth selective coupler 368 is placed in thedisengaged configuration and second selective coupler 364 is placed inthe engaged configuration.

FIG. 9 is a diagrammatic representation of a multi-speed transmission500. Multi-speed transmission 500 includes an input member 502 and anoutput member 504. Each of input member 502 and output member 504 isrotatable relative to at least one stationary member 506. An exemplaryinput member 502 is an input shaft or other suitable rotatablecomponent. An exemplary output member 504 is an output shaft or othersuitable rotatable component. An exemplary stationary member 506 is ahousing of multi-speed transmission 500. The housing may include severalcomponents coupled together.

Multi-speed transmission 500 includes a plurality of planetary gearsets,illustratively a first planetary gearset 508, a second planetary gearset510, a third planetary gearset 512, and a fourth planetary gearset 514.In one embodiment, additional planetary gearsets may be included.Further, although first planetary gearset 508, second planetary gearset510, third planetary gearset 512, and fourth planetary gearset 514 areillustrated as simple planetary gearsets, it is contemplated thatcompound planetary gearsets may be included in some embodiments.

In one embodiment, multi-speed transmission 500 is arranged asillustrated in FIG. 9, with first planetary gearset 508 positionedbetween a first location or end 516 at which input member 502 entersstationary member 506 and second planetary gearset 510, second planetarygearset 510 is positioned between first planetary gearset 508 and thirdplanetary gearset 512, third planetary gearset 512 is positioned betweensecond planetary gearset 510 and fourth planetary gearset 514, andfourth planetary gearset 514 is positioned between third planetarygearset 512 and a second location or end 518 at which output member 504exits stationary member 506. In alternative embodiments, first planetarygearset 508, second planetary gearset 510, third planetary gearset 512,and fourth planetary gearset 514 are arranged in any order relative tolocation 516 and location 518. In the illustrated embodiment of FIG. 9,each of first planetary gearset 508, second planetary gearset 510, thirdplanetary gearset 512, and fourth planetary gearset 514 are axiallyaligned. In one example, input member 502 and output member 504 are alsoaxially aligned with first planetary gearset 508, second planetarygearset 510, third planetary gearset 512, and fourth planetary gearset514. In alternative embodiments, one or more of input member 502, outputmember 504, first planetary gearset 508, second planetary gearset 510,third planetary gearset 512, and fourth planetary gearset 514 are offsetand not axially aligned with the remainder.

First planetary gearset 508 includes a sun gear 520, a planet carrier522 supporting a plurality of planet gears 524, and a ring gear 526.Second planetary gearset 510 includes a sun gear 530, a planet carrier532 supporting a plurality of planet gears 534, and a ring gear 536.Third planetary gearset 512 includes a sun gear 540, a planet carrier542 supporting a plurality of planet gears 544, and a ring gear 546.Fourth planetary gearset 514 includes a sun gear 550, a planet carrier552 supporting a plurality of planet gears 554, and a ring gear 556.

Multi-speed transmission 500 further includes a plurality of selectivecouplers, illustratively a first selective coupler 562, a secondselective coupler 564, a third selective coupler 566, a fourth selectivecoupler 568, a fifth selective coupler 570, and a sixth selectivecoupler 572. In the illustrated embodiment, first selective coupler 562and second selective coupler 564 are brakes and third selective coupler566, fourth selective coupler 568, fifth selective coupler 570, andsixth selective coupler 572 are clutches. The axial locations of theclutches and brakes relative to the plurality of planetary gearsets maybe altered from the illustrated axial locations. In alternativeembodiments, any number of clutches and brakes may be used.

Multi-speed transmission 500 includes several components that areillustratively shown as being fixedly coupled together. Input member 502is fixedly coupled to sun gear 520 of first planetary gearset 508.Output member 504 is fixedly coupled to planet carrier 552 of fourthplanetary gearset 514 and ring gear 546 of third planetary gearset 512.Ring gear 526 of first planetary gearset 508 and sun gear 540 of thirdplanetary gearset 512 are fixedly coupled together. Planet carrier 522of first planetary gearset 508 is fixedly coupled to ring gear 536 ofsecond planetary gearset 510. Planet carrier 542 of third planetarygearset 512 is fixedly coupled to ring gear 556 of fourth planetarygearset 514. In alternative embodiments, one or more of the componentsfixedly coupled together are selectively coupled together through one ormore selective couplers.

Multi-speed transmission 500 may be described as having eightinterconnectors. Input member 502 is a first interconnector that bothprovides input torque to multi-speed transmission 500 and fixedlycouples sun gear 520 of first planetary gearset 508 to third selectivecoupler 566 and to fourth selective coupler 568. Output member 504 is asecond interconnector that provides output torque from multi-speedtransmission 500 and fixedly couples planet carrier 552 of fourthplanetary gearset 514 to ring gear 546 of third planetary gearset 512. Athird interconnector 580 fixedly couples ring gear 526 of firstplanetary gearset 508 to sun gear 540 of third planetary gearset 512.Third interconnector 580 is further fixedly coupled to fifth selectivecoupler 570. A fourth interconnector 582 fixedly couples planet carrier522 of first planetary gearset 508 to ring gear 536 of second planetarygearset 510. A fifth interconnector 584 fixedly couples planet carrier542 of third planetary gearset 512 to ring gear 556 of fourth planetarygearset 514. Fifth interconnector 584 is further fixedly coupled tothird selective coupler 566 and to sixth selective coupler 572. A sixthinterconnector 586 fixedly couples sun gear 550 of fourth planetarygearset 514 to fourth selective coupler 568. A seventh interconnector588 fixedly couples planet carrier 532 of second planetary gearset 510to first selective coupler 562 and to fifth selective coupler 570. Aneighth interconnector 590 fixedly couples sun gear 530 of secondplanetary gearset 510 to second selective coupler 564 and to sixthselective coupler 572.

Multi-speed transmission 500 further includes several components thatare illustratively shown as being selectively coupled together throughselective couplers. First selective coupler 562, when engaged, fixedlycouples planet carrier 532 of second planetary gearset 510 to stationarymember 506. When first selective coupler 562 is disengaged, planetcarrier 532 of second planetary gearset 510 may rotate relative tostationary member 506.

Second selective coupler 564, when engaged, fixedly couples sun gear 530of second planetary gearset 510 to stationary member 506. When secondselective coupler 564 is disengaged, sun gear 530 of second planetarygearset 510 may rotate relative to stationary member 506.

Third selective coupler 566, when engaged, fixedly couples planetcarrier 542 of third planetary gearset 512 and ring gear 556 of fourthplanetary gearset 514 to sun gear 520 of first planetary gearset 508.When third selective coupler 566 is disengaged, planet carrier 542 ofthird planetary gearset 512 and ring gear 556 of fourth planetarygearset 514 may rotate relative to sun gear 520 of first planetarygearset 508.

Fourth selective coupler 568, when engaged, fixedly couples sun gear 520of first planetary gearset 508 to sun gear 550 of fourth planetarygearset 514. When fourth selective coupler 568 is disengaged, sun gear550 of fourth planetary gearset 514 may rotate relative to sun gear 520of first planetary gearset 508.

Fifth selective coupler 570, when engaged, fixedly couples ring gear 526of first planetary gearset 508 and sun gear 540 of third planetarygearset 512 to planet carrier 532 of second planetary gearset 510. Whenfifth selective coupler 570 is disengaged, ring gear 526 of firstplanetary gearset 508 and sun gear 540 of third planetary gearset 512may rotate relative to planet carrier 532 of second planetary gearset510.

Sixth selective coupler 572, when engaged, fixedly couples planetcarrier 542 of third planetary gearset 512 and ring gear 556 of fourthplanetary gearset 514 to sun gear 530 of second planetary gearset 510and to second selective coupler 564. When sixth selective coupler 572 isdisengaged, planet carrier 542 of third planetary gearset 512 and ringgear 556 of fourth planetary gearset 514 may rotate relative to sun gear530 of second planetary gearset 510.

By engaging various combinations of first selective coupler 562, secondselective coupler 564, third selective coupler 566, fourth selectivecoupler 568, fifth selective coupler 570, and sixth selective coupler572, additional components of multi-speed transmission 500 may befixedly coupled together.

The plurality of planetary gearsets and the plurality of selectivecouplers of multi-speed transmission 500 may be interconnected invarious arrangements to provide torque from input member 502 to outputmember 504 in at least nine forward gear or speed ratios and one reversegear or speed ratio. Referring to FIG. 10, an exemplary truth table 600is shown that provides the state of each of first selective coupler 562,second selective coupler 564, third selective coupler 566, fourthselective coupler 568, fifth selective coupler 570, and sixth selectivecoupler 572 for ten different forward gear or speed ratios and onereverse gear or speed ratio. Each row corresponds to a giveninterconnection arrangement for transmission 500. The first columnprovides the gear range (reverse and 1st-10^(th) forward gears). Thesecond column provides the gear ratio between the input member 502 andthe output member 504. The third column provides the gear step. The sixrightmost columns illustrate which ones of the selective couplers562-572 are engaged (“1” indicates engaged) and which ones of selectivecouplers 562-572 are disengaged (“(blank)” indicates disengaged). FIG.10 is only one example of any number of truth tables possible forachieving at least nine forward ratios and one reverse ratio.

In the example of FIG. 10, the illustrated reverse ratio (Rev) isachieved by having second selective coupler 564, fifth selective coupler570, and sixth selective coupler 572 in an engaged configuration andfirst selective coupler 562, third selective coupler 566, and fourthselective coupler 568 in a disengaged configuration.

In one embodiment, to place multi-speed transmission 500 in neutral(Neu), all of first selective coupler 562, second selective coupler 564,third selective coupler 566, fourth selective coupler 568, fifthselective coupler 570, and sixth selective coupler 572 are in thedisengaged configuration. One or more of first selective coupler 562,second selective coupler 564, third selective coupler 566, fourthselective coupler 568, fifth selective coupler 570, and sixth selectivecoupler 572 may remain engaged in neutral (Neu) as long as thecombination of first selective coupler 562, second selective coupler564, third selective coupler 566, fourth selective coupler 568, fifthselective coupler 570, and sixth selective coupler 572 does not transmittorque from input member 502 to output member 504.

A first forward ratio (shown as 1st) in truth table 600 of FIG. 10 isachieved by having first selective coupler 562, second selective coupler564, and sixth selective coupler 572 in an engaged configuration andthird selective coupler 566, fourth selective coupler 568, and fifthselective coupler 570 in a disengaged configuration.

A second or subsequent forward ratio (shown as 2nd) in truth table 600of FIG. 10 is achieved by having second selective coupler 564, fourthselective coupler 568, and sixth selective coupler 572 in an engagedconfiguration and first selective coupler 562, third selective coupler566, and fifth selective coupler 570 in a disengaged configuration.Therefore, when transitioning between the first forward ratio and thesecond forward ratio, first selective coupler 562 is placed in thedisengaged configuration and fourth selective coupler 568 is placed inthe engaged configuration.

A third or subsequent forward ratio (shown as 3rd) in truth table 600 ofFIG. 10 is achieved by having first selective coupler 562, secondselective coupler 564, and fourth selective coupler 568 in an engagedconfiguration and third selective coupler 566, fifth selective coupler570, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the second forward ratio and thethird forward ratio, sixth selective coupler 572 is placed in thedisengaged configuration and first selective coupler 562 is placed inthe engaged configuration.

A fourth or subsequent forward ratio (shown as 4th) in truth table 600of FIG. 10 is achieved by having first selective coupler 562, fourthselective coupler 568, and fifth selective coupler 570 in an engagedconfiguration and second selective coupler 564, third selective coupler566, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the third forward ratio and thefourth forward ratio, second selective coupler 564 is placed in thedisengaged configuration and fifth selective coupler 570 is placed inthe engaged configuration.

A fifth or subsequent forward ratio (shown as 5th) in truth table 600 ofFIG. 10 is achieved by having second selective coupler 564, fourthselective coupler 568, and fifth selective coupler 570 in an engagedconfiguration and first selective coupler 562, third selective coupler566, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the fourth forward ratio and thefifth forward ratio, first selective coupler 562 is placed in thedisengaged configuration and second selective coupler 564 is placed inthe engaged configuration.

A sixth or subsequent forward ratio (shown as 6th) in truth table 600 ofFIG. 10 is achieved by having second selective coupler 564, thirdselective coupler 566, and fourth selective coupler 568 in an engagedconfiguration and first selective coupler 562, fifth selective coupler570, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the fifth forward ratio and thesixth forward ratio, fifth selective coupler 570 is placed in thedisengaged configuration and third selective coupler 566 is placed inthe engaged configuration.

A seventh or subsequent forward ratio (shown as 7th) in truth table 600of FIG. 10 is achieved by having second selective coupler 564, thirdselective coupler 566, and fifth selective coupler 570 in an engagedconfiguration and first selective coupler 562, fourth selective coupler568, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the sixth forward ratio and theseventh forward ratio, fourth selective coupler 568 is placed in thedisengaged configuration and fifth selective coupler 570 is placed inthe engaged configuration.

An eighth or subsequent forward ratio (shown as 8th) in truth table 600of FIG. 10 is achieved by having first selective coupler 562, thirdselective coupler 566, and fifth selective coupler 570 in an engagedconfiguration and second selective coupler 564, fourth selective coupler568, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the seventh forward ratio and theeighth forward ratio, second selective coupler 564 is placed in thedisengaged configuration and first selective coupler 562 is placed inthe engaged configuration.

A ninth or subsequent forward ratio (shown as 9th) in truth table 600 ofFIG. 10 is achieved by having first selective coupler 562, secondselective coupler 564, and third selective coupler 566 in an engagedconfiguration and fourth selective coupler 568, fifth selective coupler570, and sixth selective coupler 572 in a disengaged configuration.Therefore, when transitioning between the eighth forward ratio and theninth forward ratio, fifth selective coupler 570 is placed in thedisengaged configuration and second selective coupler 564 is placed inthe engaged configuration.

A tenth or subsequent forward ratio (shown as 10th) in truth table 600of FIG. 10 is achieved by having first selective coupler 562, thirdselective coupler 566, and sixth selective coupler 572 in an engagedconfiguration and second selective coupler 564, fourth selective coupler568, and fifth selective coupler 570 in a disengaged configuration.Therefore, when transitioning between the ninth forward ratio and thetenth forward ratio, second selective coupler 564 is placed in thedisengaged configuration and sixth selective coupler 572 is placed inthe engaged configuration.

Referring to FIG. 11, another exemplary multi-speed transmission 650 isillustrated. The kinematics of multi-speed transmission 650 aregenerally identical to multi-speed transmission 500 with the followingexceptions. First, sixth selective coupler 654 of multi-speedtransmission 650, when engaged, fixedly couples planet carrier 542 ofthird planetary gearset 512 and ring gear 556 of fourth planetarygearset 514 to stationary member 506, not to sun gear 530 of secondplanetary gearset 510 as accomplished by sixth selective coupler 572 ofmulti-speed transmission 500. When sixth selective coupler 654 ofmulti-speed transmission 650 is disengaged, planet carrier 542 of thirdplanetary gearset 512 and ring gear 556 of fourth planetary gearset 514may rotate relative to stationary member 506. Second, interconnector 652of multi-speed transmission 650 fixedly couples sun gear 530 of secondplanetary gearset 510 to second selective coupler 564, but not also tothe sixth selective coupler as accomplished by eighth interconnector 590of multi-speed transmission 500. Multi-speed transmission 650 has anequal number of clutches, third selective coupler 566, fourth selectivecoupler 568, and fifth selective coupler 570, and brakes, firstselective coupler 562, second selective coupler 564, and sixth selectivecoupler 654.

The plurality of planetary gearsets and the plurality of selectivecouplers of multi-speed transmission 650 may be interconnected invarious arrangements to provide torque from input member 502 to outputmember 504 in at least nine forward gear or speed ratios and one reversegear or speed ratio. Referring to FIG. 12, an exemplary truth table 660is shown that provides the state of each of first selective coupler 562,second selective coupler 564, third selective coupler 566, fourthselective coupler 568, fifth selective coupler 570, and sixth selectivecoupler 654 for nine different forward gear or speed ratios and onereverse gear or speed ratio. Each row corresponds to a giveninterconnection arrangement for transmission 650. The first columnprovides the gear range (reverse and 1^(th)-9^(th) forward gears). Thesecond column provides the gear ratio between the input member 502 andthe output member 504. The third column provides the gear step. The sixrightmost columns illustrate which ones of the selective couplers562-570 and 654 are engaged (“1” indicates engaged) and which ones ofselective couplers 562-570 and 654 are disengaged (“(blank)” indicatesdisengaged). FIG. 12 is only one example of any number of truth tablespossible for achieving at least nine forward ratios and one reverseratio.

In the example of FIG. 12, the illustrated reverse ratio (Rev) isachieved by having second selective coupler 564, fifth selective coupler570, and sixth selective coupler 654 in an engaged configuration andfirst selective coupler 562, third selective coupler 566, and fourthselective coupler 568 in a disengaged configuration.

In one embodiment, to place multi-speed transmission 650 in neutral(Neu), all of first selective coupler 562, second selective coupler 564,third selective coupler 566, fourth selective coupler 568, fifthselective coupler 570, and sixth selective coupler 654 are in thedisengaged configuration. One or more of first selective coupler 562,second selective coupler 564, third selective coupler 566, fourthselective coupler 568, fifth selective coupler 570, and sixth selectivecoupler 654 may remain engaged in neutral (Neu) as long as thecombination of first selective coupler 562, second selective coupler564, third selective coupler 566, fourth selective coupler 568, fifthselective coupler 570, and sixth selective coupler 654 does not transmittorque from input member 502 to output member 504.

A first forward ratio (shown as 1st) in truth table 660 of FIG. 12 isachieved by having first selective coupler 562, second selective coupler564, and sixth selective coupler 654 in an engaged configuration andthird selective coupler 566, fourth selective coupler 568, and fifthselective coupler 570 in a disengaged configuration.

A second or subsequent forward ratio (shown as 2nd) in truth table 660of FIG. 12 is achieved by having second selective coupler 564, fourthselective coupler 568, and sixth selective coupler 654 in an engagedconfiguration and first selective coupler 562, third selective coupler566, and fifth selective coupler 570 in a disengaged configuration.Therefore, when transitioning between the first forward ratio and thesecond forward ratio, first selective coupler 562 is placed in thedisengaged configuration and fourth selective coupler 568 is placed inthe engaged configuration.

A third or subsequent forward ratio (shown as 3rd) in truth table 660 ofFIG. 12 is achieved by having first selective coupler 562, secondselective coupler 564, and fourth selective coupler 568 in an engagedconfiguration and third selective coupler 566, fifth selective coupler570, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the second forward ratio and thethird forward ratio, sixth selective coupler 654 is placed in thedisengaged configuration and first selective coupler 562 is placed inthe engaged configuration.

A fourth or subsequent forward ratio (shown as 4th) in truth table 660of FIG. 12 is achieved by having first selective coupler 562, fourthselective coupler 568, and fifth selective coupler 570 in an engagedconfiguration and second selective coupler 564, third selective coupler566, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the third forward ratio and thefourth forward ratio, second selective coupler 564 is placed in thedisengaged configuration and fifth selective coupler 570 is placed inthe engaged configuration.

A fifth or subsequent forward ratio (shown as 5th) in truth table 660 ofFIG. 12 is achieved by having second selective coupler 564, fourthselective coupler 568, and fifth selective coupler 570 in an engagedconfiguration and first selective coupler 562, third selective coupler566, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the fourth forward ratio and thefifth forward ratio, first selective coupler 562 is placed in thedisengaged configuration and second selective coupler 564 is placed inthe engaged configuration.

A sixth or subsequent forward ratio (shown as 6th) in truth table 660 ofFIG. 12 is achieved by having second selective coupler 564, thirdselective coupler 566, and fourth selective coupler 568 in an engagedconfiguration and first selective coupler 562, fifth selective coupler570, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the fifth forward ratio and thesixth forward ratio, fifth selective coupler 570 is placed in thedisengaged configuration and third selective coupler 566 is placed inthe engaged configuration.

A seventh or subsequent forward ratio (shown as 7th) in truth table 660of FIG. 12 is achieved by having second selective coupler 564, thirdselective coupler 566, and fifth selective coupler 570 in an engagedconfiguration and first selective coupler 562, fourth selective coupler568, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the sixth forward ratio and theseventh forward ratio, fourth selective coupler 568 is placed in thedisengaged configuration and fifth selective coupler 570 is placed inthe engaged configuration.

An eighth or subsequent forward ratio (shown as 8th) in truth table 660of FIG. 12 is achieved by having first selective coupler 562, thirdselective coupler 566, and fifth selective coupler 570 in an engagedconfiguration and second selective coupler 564, fourth selective coupler568, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the seventh forward ratio and theeighth forward ratio, second selective coupler 564 is placed in thedisengaged configuration and first selective coupler 562 is placed inthe engaged configuration.

A ninth or subsequent forward ratio (shown as 9th) in truth table 660 ofFIG. 12 is achieved by having first selective coupler 562, secondselective coupler 564, and third selective coupler 566 in an engagedconfiguration and fourth selective coupler 568, fifth selective coupler570, and sixth selective coupler 654 in a disengaged configuration.Therefore, when transitioning between the eighth forward ratio and theninth forward ratio, fifth selective coupler 570 is placed in thedisengaged configuration and second selective coupler 564 is placed inthe engaged configuration.

The present disclosure contemplates that downshifts follow the reversesequence of the corresponding upshift (as described above). Further,several power-on skip-shifts that are single-transition are possible(e.g. from 1^(th) up to 3^(rd), from 3^(rd) down to 1^(th), from 3^(rd)up to 5^(th), and from 5^(th) down to 3^(rd)).

In the illustrated embodiments, various combinations of three of theavailable selective couplers are engaged for each of the illustratedforward speed ratios and reverse speed ratios. Additional forward speedratios and reverse speed ratios are possible based on other combinationsof engaged selective couplers. Although in the illustrated embodiments,each forward speed ratio and reverse speed ratio has three of theavailable selective couplers engaged, it is contemplated that less thanthree and more than three selective couplers may be engaged at the sametime.

While this invention has been described as having exemplary designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. A transmission comprising: at least onestationary member; an input member rotatable relative to the at leastone stationary member; a plurality of planetary gearsets operativelycoupled to the input member, each of the plurality of planetary gearsetsincluding a first gearset component, a second gearset component, and athird gearset component, the plurality of planetary gearsets including afirst planetary gearset, a second planetary gearset, a third planetarygearset, and a fourth planetary gearset, the input member is fixedlycoupled to the first gearset component of the first planetary gearset;an output member operatively coupled to the input member through theplurality of planetary gearsets and rotatable relative to the at leastone stationary member, the output member is fixedly coupled to thefourth planetary gearset; a first interconnector fixedly couples thesecond gearset component of the first planetary gearset to the secondplanetary gearset; a second interconnector fixedly couples the thirdgearset component of the first planetary gearset to the third planetarygearset; a third interconnector fixedly couples the second gearsetcomponent of the third planetary gearset to the third gearset componentof the fourth planetary gearset; and a plurality of selective couplers,wherein the plurality of selective couplers include a first number ofclutches and a second number of brakes, wherein the first number is atleast equal to the second number.
 2. The transmission of claim 1,wherein the second gearset component of the first planetary gearset isfixedly coupled to the third gearset component of the second planetarygearset.
 3. The transmission of claim 1, wherein the third gearsetcomponent of the first planetary gearset is fixedly coupled to the firstgearset component of the third planetary gearset.
 4. The transmission ofclaim 1, wherein the output member is fixedly coupled to the secondgearset component of the fourth planetary gearset.
 5. The transmissionof claim 4, wherein the output member is further fixedly coupled to thethird planetary gearset.
 6. The transmission of claim 5, wherein theoutput member is further fixedly coupled to the third gearset componentof the third planetary gearset.
 7. The transmission of claim 1, whereinthe at least one stationary member includes a housing, the housinghaving a first end and a second end, wherein the input member isaccessible proximate the first end of the housing; the output member isaccessible proximate the second end of the housing; the first planetarygearset is positioned between the first end of the housing and thesecond planetary gearset; the second planetary gearset is positionedbetween the first planetary gearset and the third planetary gearset; thethird planetary gearset is positioned between the second planetarygearset and the fourth planetary gearset; and the fourth planetarygearset is positioned between the third planetary gearset and the secondend of the housing.
 8. The transmission of claim 7, wherein each of thefirst planetary gearset, the second planetary gearset, the thirdplanetary gearset, and the fourth planetary gearset is a simpleplanetary gearset.
 9. The transmission of claim 8, wherein the firstgearset component of the first planetary gearset is a first sun gear,the first gearset component of the second planetary gearset is a secondsun gear, the first gearset component of the third planetary gearset isa third sun gear, the first gearset component of the fourth planetarygearset is a fourth sun gear, the second gearset component of the firstplanetary gearset is a first planet carrier, the second gearsetcomponent of the second planetary gearset is a second planet carrier,the second gearset component of the third planetary gearset is a thirdplanet carrier, the second gearset component of the fourth planetarygearset is a fourth planet carrier, the third gearset component of thefirst planetary gearset is a first ring gear, the third gearsetcomponent of the second planetary gearset is a second ring gear, thethird gearset component of the third planetary gearset is a third ringgear, and the third gearset component of the fourth planetary gearset isa fourth ring gear.
 10. The transmission of claim 1, wherein theplurality of selective couplers include: a first selective couplerwhich, when engaged, fixedly couples the second gearset component of thesecond planetary gearset to the at least one stationary member; a secondselective coupler which, when engaged, fixedly couples the first gearsetcomponent of the second planetary gearset to the at least one stationarymember; a third selective coupler which, when engaged, fixedly couplesthe second gearset component of the third planetary gearset and thethird gearset component of the fourth planetary gearset to the firstgearset component of the first planetary gearset; a fourth selectivecoupler which, when engaged, fixedly couples the first gearset componentof the first planetary gearset to the first gearset component of thefourth planetary gearset; a fifth selective coupler which, when engaged,fixedly couples the third gearset component of the first planetarygearset and the first gearset component of the third planetary gearsetto the second gearset component of the second planetary gearset; and asixth selective coupler which, when engaged, fixedly couples the secondgearset component of the third planetary gearset and the third gearsetcomponent of the fourth planetary gearset to the at least one stationarymember.
 11. A transmission comprising: at least one stationary member;an input member rotatable relative to the at least one stationarymember; a plurality of planetary gearsets operatively coupled to theinput member, each of the plurality of planetary gearsets including afirst gearset component, a second gearset component, and a third gearsetcomponent, the plurality of planetary gearsets including a firstplanetary gearset, a second planetary gearset, a third planetarygearset, and a fourth planetary gearset, the input member is fixedlycoupled to the first gearset component of the first planetary gearset;an output member operatively coupled to the input member through theplurality of planetary gearsets and rotatable relative to the at leastone stationary member, the output member is fixedly coupled to thefourth planetary gearset; a first interconnector fixedly couples thesecond gearset component of the first planetary gearset to the secondplanetary gearset; a second interconnector fixedly couples the thirdgearset component of the first planetary gearset to the third planetarygearset; and a plurality of selective couplers, wherein the plurality ofselective couplers include a first number of clutches and a secondnumber of brakes, wherein the first number is at least equal to thesecond number, wherein the plurality of selective couplers include: afirst selective coupler which, when engaged, fixedly couples the secondgearset component of the second planetary gearset to the at least onestationary member; a second selective coupler which, when engaged,fixedly couples the first gearset component of the second planetarygearset to the at least one stationary member; a third selective couplerwhich, when engaged, fixedly couples the second gearset component of thethird planetary gearset and the third gearset component of the fourthplanetary gearset to the first gearset component of the first planetarygearset; a fourth selective coupler which, when engaged, fixedly couplesthe first gearset component of the first planetary gearset to the firstgearset component of the fourth planetary gearset; a fifth selectivecoupler which, when engaged, fixedly couples the third gearset componentof the first planetary gearset and the first gearset component of thethird planetary gearset to the second gearset component of the secondplanetary gearset; and a sixth selective coupler which, when engaged,fixedly couples the second gearset component of the third planetarygearset and the third gearset component of the fourth planetary gearsetto the at least one stationary member.
 12. The transmission of claim 11,wherein the plurality of selective couplers are selectively engaged in aplurality of combinations to establish at least nine forward speedratios and at least one reverse speed ratio between the input member andthe output member, each of the plurality of combinations having at leastthree of the plurality of selective couplers engaged.
 13. Thetransmission of claim 12, wherein in a first forward speed ratio, thefirst selective coupler, the second selective coupler, and the sixthselective coupler are engaged.
 14. The transmission of claim 13, whereinin a second forward speed ratio, the second selective coupler, thefourth selective coupler, and the sixth selective coupler are engaged.15. The transmission of claim 14, wherein in a third forward speedratio, the first selective coupler, the second selective coupler, andthe fourth selective coupler are engaged.
 16. The transmission of claim15, wherein in a fourth forward speed ratio, the second selectivecoupler, the fourth selective coupler, and the fifth selective couplerare engaged.
 17. The transmission of claim 16, wherein in a fifthforward speed ratio, the second selective coupler, the third selectivecoupler, and the sixth selective coupler are engaged.
 18. Thetransmission of claim 17, wherein in a sixth forward speed ratio, thesecond selective coupler, the third selective coupler, and the fifthselective coupler are engaged.
 19. The transmission of claim 18, whereinin a seventh forward speed ratio, the first selective coupler, thesecond selective coupler, and the third selective coupler are engaged.20. The transmission of claim 19, wherein in a first reverse speedratio, the second selective coupler, the fifth selective coupler, andthe sixth selective coupler are engaged.